<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>行内块和行内元素文本对齐问题</title>
  <style type="text/css">
    .block{
      display: inline-block;
      width: 150px;
      height: 100px;
      border: 1px solid #000;
      vertical-align: middle;
    }
  </style>
</head>
<body>
  <span class="block">123</span>
  <span>123</span>
</body>
</html>